Chronic Nicotine Treatment Impacts the Regulation of Opioid and Non-opioid Peptides in the Rat Dorsal Striatum

Abstract

The chronic use of nicotine, the main psychoactive ingredient of tobacco smoking, alters diverse physiological processes and consequently generates physical dependence. To understand the impact of chronic nicotine on neuropeptides, which are potential molecules associated with dependence, we conducted qualitative and quantitative neuropeptidomics on the rat dorsal striatum, an important brain region implicated in the preoccupation/craving phase of drug dependence. We used extensive LC-FT-MS/MS analyses for neuropeptide identification and LC-FT-MS in conjunction with stable isotope addition for relative quantification. The treatment with chronic nicotine for 3 months led to moderate changes in the levels of endogenous dorsal striatum peptides. Five enkephalin opioid peptides were up-regulated, although no change was observed for dynorphin peptides. Specially, nicotine altered levels of nine non-opioid peptides derived from precursors, including somatostatin and cerebellin, which potentially modulate neurotransmitter release and energy metabolism. This broad but selective impact on the multiple peptidergic systems suggests that apart from the opioid peptides, several other peptidergic systems are involved in the preoccupation/craving phase of drug dependence. Our finding permits future evaluation of the neurochemical circuits modulated by chronic nicotine exposure and provides a number of novel molecules that could serve as potential therapeutic targets for treating drug dependence. The chronic use of nicotine, the main psychoactive ingredient of tobacco smoking, alters diverse physiological processes and consequently generates physical dependence. To understand the impact of chronic nicotine on neuropeptides, which are potential molecules associated with dependence, we conducted qualitative and quantitative neuropeptidomics on the rat dorsal striatum, an important brain region implicated in the preoccupation/craving phase of drug dependence. We used extensive LC-FT-MS/MS analyses for neuropeptide identification and LC-FT-MS in conjunction with stable isotope addition for relative quantification. The treatment with chronic nicotine for 3 months led to moderate changes in the levels of endogenous dorsal striatum peptides. Five enkephalin opioid peptides were up-regulated, although no change was observed for dynorphin peptides. Specially, nicotine altered levels of nine non-opioid peptides derived from precursors, including somatostatin and cerebellin, which potentially modulate neurotransmitter release and energy metabolism. This broad but selective impact on the multiple peptidergic systems suggests that apart from the opioid peptides, several other peptidergic systems are involved in the preoccupation/craving phase of drug dependence. Our finding permits future evaluation of the neurochemical circuits modulated by chronic nicotine exposure and provides a number of novel molecules that could serve as potential therapeutic targets for treating drug dependence. Nicotine is the main psychoactive ingredient of tobacco (1De Biasi M. Dani J.A. Reward, addiction, withdrawal to nicotine.Annu. Rev. Neurosci. 2011; 34: 105-130Crossref PubMed Scopus (279) Google Scholar). By acting on the nicotinic acetylcholine receptors located in diverse brain areas, nicotine generates psychoactive effects such as euphoria, reduced stress, increased energy, and enhanced cognitive functions (2Benowitz N.L. Nicotine addiction.N. Engl. J. Med. 2010; 362: 2295-2303Crossref PubMed Scopus (989) Google Scholar). Chronic nicotine use alters various aspects of neurochemical transmission and has a strong impact on diverse physiological processes (2Benowitz N.L. Nicotine addiction.N. Engl. J. Med. 2010; 362: 2295-2303Crossref PubMed Scopus (989) Google Scholar), resulting in drug-seeking and drug-taking behaviors for normal smokers and for a considerable number of patients suffering from schizophrenia and Alzheimer disease, who use nicotine for self-medication (3Sherr J.D. Myers C. Avila M.T. Elliott A. Blaxton T.A. Thaker G.K. The effects of nicotine on specific eye tracking measures in schizophrenia.Biol. Psychiatry. 2002; 52: 721-728Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar, 4Knott V. Mohr E. Mahoney C. Engeland C. Ilivitsky V. Effects of acute nicotine administration on cognitive event-related potentials in tacrine-treated and non-treated patients with Alzheimer disease.Neuropsychobiology. 2002; 45: 156-160Crossref PubMed Scopus (17) Google Scholar). The dorsal striatum (DS) 1The abbreviations used are:DSdorsal striatumGABAγ-aminobutyric acidLTQlinear trap quadrupoleMOCmixing on columnPENK Apro-enkephalin APDYNpro-dynorphinPOMCpro-opiomelanocortin. 1The abbreviations used are:DSdorsal striatumGABAγ-aminobutyric acidLTQlinear trap quadrupoleMOCmixing on columnPENK Apro-enkephalin APDYNpro-dynorphinPOMCpro-opiomelanocortin. is one of the key brain regions that has been associated with neural regulation during chronic nicotine exposure (5Yalachkov Y. Kaiser J. Naumer M.J. Brain regions related to tool use and action knowledge reflect nicotine dependence.J. Neurosci. 2009; 29: 4922-4929Crossref PubMed Scopus (73) Google Scholar). In particular, the DS is involved in habit formation during the preoccupation/craving (later) phase of nicotine dependence characterized by compulsive drug-taking (6Koob G.F. Volkow N.D. Neurocircuitry of addiction.Neuropsychopharmacology. 2010; 35: 217-238Crossref PubMed Scopus (3517) Google Scholar). Behavioral changes associated with nicotine dependence have been linked to small molecule neurotransmitter systems, including the glutamate and dopamine system in the DS (7Xiao C. Nashmi R. McKinney S. Cai H. McIntosh J.M. Lester H.A. Chronic nicotine selectively enhances α4β2* nicotinic acetylcholine receptors in the nigrostriatal dopamine pathway.J. Neurosci. 2009; 29: 12428-12439Crossref PubMed Scopus (85) Google Scholar). The DS is also known to contain diverse neuropeptides, many of which are probably critical mediators of physiological processes that are associated with nicotine, such as the regulation of reinforcement and energy metabolism. However, neuropeptides have not been extensively investigated in the DS during long periods of nicotine administration. dorsal striatum γ-aminobutyric acid linear trap quadrupole mixing on column pro-enkephalin A pro-dynorphin pro-opiomelanocortin. dorsal striatum γ-aminobutyric acid linear trap quadrupole mixing on column pro-enkephalin A pro-dynorphin pro-opiomelanocortin. Immunoassay studies have shown that neuropeptides, including substance P, neuropeptide Y, and opioid peptides, including the enkephalins, are expressed by inhibitory neurons (8Rice M.W. Roberts R.C. Melendez-Ferro M. Perez-Costas E. Neurochemical characterization of the tree shrew dorsal striatum.Front. Neuroanat. 2011; 5: 53Crossref PubMed Scopus (22) Google Scholar), which make up a large majority of the neurons in the DS (9Graveland G.A. DiFiglia M. The frequency and distribution of medium-sized neurons with indented nuclei in the primate and rodent neostriatum.Brain Res. 1985; 327: 307-311Crossref PubMed Scopus (209) Google Scholar). Many of these inhibitory GABAergic neurons express nicotinic cholinergic receptors (10Zhou F.-M. Wilson C.J. Dani J.A. Cholinergic interneuron characteristics and nicotinic properties in the striatum.J. Neurobiol. 2002; 53: 590-605Crossref PubMed Scopus (330) Google Scholar), suggesting that nicotine administration may regulate their activity, leading to variations in the release of neuropeptides, as well as the inhibitory neurotransmitter GABA. Previous investigations of peptide regulation during chronic nicotine administration in the striatum have exclusively focused on the class of opioid peptides, which are thought to play an important role in the control of diverse physiological processes, including reward processing, nociception, and regulation of emotions (11Bodnar R.J. Hadjimarkou M.M. Endogenous opiates and behavior: 2002.Peptides. 2003; 24: 1241-1302Crossref PubMed Scopus (41) Google Scholar, 12Hadjiconstantinou M. Neff N.H. Nicotine and endogenous opioids: neurochemical and pharmacological evidence.Neuropharmacology. 2011; 60: 1209-1220Crossref PubMed Scopus (71) Google Scholar). Available studies have focused on the analysis of three opioid peptides, their precursors, or receptors as follows: met-enkephalin, dynorphin, and β-endorphin, using conventional techniques like immunoassays (13McCollum L.A. Roche J.K. Roberts R.C. Immunohistochemical localization of enkephalin in the human striatum: A postmortem ultrastructural study.Synapse. 2012; 66: 204-219Crossref PubMed Scopus (5) Google Scholar, 14Isola R. Zhang H. G.A. Neff N.H. M. and changes in the striatum during nicotine PubMed Scopus Google Scholar). is considerable in changes of peptide levels in the striatum during chronic nicotine administration. are with nicotine for increased in the striatum T.A. G.A. Neff N.H. M. and are increased in striatum treatment with PubMed Scopus Google Scholar). By is reduced in the striatum are with nicotine for T.A. G.A. The of chronic administration of nicotine on opioid and levels in Res. PubMed Scopus Google Scholar). A number of to observed including the of and of as studies have a opioid is peptide for these well opioid peptides. In addition to these opioid peptides, the DS peptides from other peptide which are also potential targets the regulation of chronic nicotine is no changes of these non-opioid peptides during chronic nicotine administration. In was to use a neuropeptidomics M. A. M. to the of novel peptides from the PubMed Scopus Google to a characterization of dorsal neuropeptides long nicotine chronic treatment in using administration. The main of is that the of many peptides from the brain derived from a drug We used a of a M. M. M. 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M. from to human studies J. PubMed Scopus Google Scholar). to such as a of to their large to In the of nicotine in the by for an was to the nicotine for smokers who The nicotine in was a for in nicotine N.L. R.J. A. M.J. M. A. J.M. J.M. on nicotine for in PubMed Scopus Google Scholar). To the peptides from of M. A. M. to the of novel peptides from the PubMed Scopus Google Scholar), control was used to the of the endogenous peptide three were by with the were and by using as M. M. M. M. of the a for Res. 2009; PubMed Scopus Google Scholar). striatum, and were from the quantitative the of were using the and the DS was from neuropeptides were as to DS We used the mixing on column identification of endogenous neuropeptides from Res. 2012; PubMed Scopus Google for brain was using the acid acid acid and acid used of of In the was by a the and the were The used to the in the of peptides. 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Neff N.H. Nicotine and endogenous opioids: neurochemical and pharmacological evidence.Neuropharmacology. 2011; 60: 1209-1220Crossref PubMed Scopus (71) Google Scholar). the that peptides no or could not to the we observed a small of the peptides nicotine administration. We also in the identification for an known neuropeptides, which are known to play an important role in the regulation of various physiological processes, but of which have not been in the of nicotine administration. Our that opioid peptides as well as a peptide in to chronic nicotine although three other opioid peptides of not changes The opioid neuropeptides are a class of neuropeptides that play a role in a number of physiological including and reward H. C. H. E. S. Endogenous opioids: and PubMed Scopus Google Scholar). In the the opioid system of peptides from three as follows: pro-enkephalin A and pro-dynorphin the opioid peptides by chronic nicotine, and the peptide are derived exclusively from derived from A and the levels for these peptides were enhanced to a with for and of and The other opioid peptides we derived from the and and no We also observed changes in a number of non-opioid peptides in We a in the of three peptides from are a of and E. Zhang A. and 2009; PubMed Scopus Google Scholar). to peptides We a large number of peptide from derived from The analysis that and increased and Chronic nicotine altered these peptides to a to In a peptide derived from increased chronic nicotine treatment We the changes of several peptides derived from other which have been associated with important functions such as and A. R. R. The and Rev. 2011; PubMed Scopus Google Scholar). peptides, and were to and is a expressed in the system and in the from are involved in physiological like and A. J. A. J. the effects of and on energy during PubMed Scopus Google Scholar, J. The of and PubMed Scopus Google Scholar). also is a involved in the of the release of other and the C. C. C. A. J. systems in and PubMed Scopus Google Scholar). A peptide derived from was of by we also a of is a peptide derived from which is for and of of the Res. Brain Res. PubMed Scopus Google Scholar, Y. J. R. is a with to the of PubMed Scopus Google Scholar). Our the effects of chronic nicotine on neuropeptides levels in the and we were to peptides from the rat these peptides, a change of peptides in the rat We the changes of in DS using and we also the of several other in chronic nicotine for the that chronic nicotine treatment also altered DS peptides that were derived from precursors, and Previous that chronic nicotine several neuropeptides such as neuropeptide J.K. Nicotine administration enhances in the rat Res. PubMed Scopus Google Scholar), J. The and in the are associated with nicotine 2011; PubMed Scopus Google Scholar), and J.K. Y. Nicotine of and receptors in rat PubMed Google in the or in the dopamine However, was chronic nicotine altered these peptides in the and we that and were in the rat suggesting of of and neurons from the to the By we known neuropeptides, including neuropeptide and in the DS was by chronic nicotine administration. The in the changes of these neuropeptide and DS the brain effects of nicotine, brain region has specific including of neurons and of nicotinic acetylcholine receptors M. nicotinic acetylcholine from to Rev. 2009; PubMed Scopus Google Scholar, The of nicotine the from molecules to Rev. Neurosci. 5: PubMed Scopus Google Scholar). In we the changes of multiple opioid peptides chronic nicotine The opioid peptides and increased chronic nicotine Our of nicotine are with of in the striatum nicotine treatment for periods of which was using T.A. G.A. Neff N.H. M. and are increased in striatum treatment with PubMed Scopus Google Scholar). the of the DS during long nicotine exposure or the preoccupation/craving of drug dependence (5Yalachkov Y. Kaiser J. Naumer M.J. Brain regions related to tool use and action knowledge reflect nicotine dependence.J. Neurosci. 2009; 29: 4922-4929Crossref PubMed Scopus (73) Google Scholar, Y. the to compulsive drug-seeking and R. PubMed Scopus Google Scholar), and the a dopamine and enkephalin systems, which are the regulation of nicotine M. Zhang H. Neff N.H. dopamine in striatum during nicotine 2011; PubMed Scopus Google Scholar). of the three peptides have not been and a of the has not been using three are derived from the by the action of the This suggests that the of these peptides may reflect with the levels in the striatum chronic nicotine T.A. G.A. Neff N.H. M. and are increased in striatum treatment with PubMed Scopus Google Scholar). class of opioid peptides, derived from including and was not modulated by chronic This is with peptides to associated with drug withdrawal R. Zhang H. G.A. Neff N.H. M. and changes in the striatum during nicotine PubMed Scopus Google Scholar), which were not in peptides are during a drug withdrawal phase but to involved during the preoccupation/craving phase of drug dependence. β-endorphin, which is an opioid peptide derived from was not in the with in the but not the DS M. Neff N.H. Nicotine and endogenous opioids: neurochemical and pharmacological evidence.Neuropharmacology. 2011; 60: 1209-1220Crossref PubMed Scopus (71) Google Scholar). In addition to opioid peptides, analysis a number of non-opioid peptides that were by chronic nicotine for peptides derived from and which to the peptide peptides are in of many of neurons and and are involved in various functions such as processes, and regulation of the of and neuropeptides The of of the and Rev. PubMed Scopus Google Scholar). peptides are with neuropeptides such as substance P, or H. The role in and PubMed Scopus Google Scholar, R. R. C. in neurons in the with substance and Neuroanat. PubMed Scopus Google Scholar), with a role of peptides in the of and peptides that we observed chronic nicotine peptides may play an role in the of and associated compulsive behaviors during the preoccupation/craving of many of the peptides the or of peptides. A number of non-opioid peptides from other peptide also a nicotine including peptides derived from the cerebellin, and peptides are thought to involved in the regulation and energy A. J. A. J. the effects of and on energy during PubMed Scopus Google Scholar, A. G.A. M. is a novel 2010; PubMed Scopus Google Scholar). is to important these peptides for the formation of and compulsive studies are to their specific in drug dependence. the changes of peptides observed in reflect the in the which is a brain region a role in drug dependence. with the brain regions associated with and processes (6Koob G.F. Volkow N.D. Neurocircuitry of addiction.Neuropsychopharmacology. 2010; 35: 217-238Crossref PubMed Scopus (3517) Google Scholar), the DS is a brain associated with which are important for the of drug dependence could habit of and Neurosci. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). an of has shown that the DS is involved in compulsive and drug-taking (5Yalachkov Y. Kaiser J. Naumer M.J. Brain regions related to tool use and action knowledge reflect nicotine dependence.J. Neurosci. 2009; 29: 4922-4929Crossref PubMed Scopus (73) Google Scholar, could habit of and Neurosci. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). Our neuropeptidomics provides a on the peptide changes of the DS the of of the peptide changes the DS to behaviors in drug dependence, which is by the and nicotine M. Neff N.H. Nicotine and endogenous opioids: neurochemical and pharmacological evidence.Neuropharmacology. 2011; 60: 1209-1220Crossref PubMed Scopus (71) Google Scholar). of the changes may also reflect to or for in other such as and their neurons are or the of chronic nicotine (10Zhou F.-M. Wilson C.J. Dani J.A. Cholinergic interneuron characteristics and nicotinic properties in the striatum.J. Neurobiol. 2002; 53: 590-605Crossref PubMed Scopus (330) Google Scholar). a these peptide may play an important role in various physiological aspects of nicotine dependence, including reward processing, the reinforcement of drug-seeking and the regulation of energy metabolism. these peptides may serve as the important of a the neurochemical of drug dependence and also as novel drug targets for treating drug dependence. We for brain with